*{
    margin:0;
    padding:0;
}
.header,
.container,
.footer{
    margin:20px auto;
}
.header{
    height: 100px;
    background-color: #c09f7a;
}
.left,
.main,
.right{
    background-color: yellow;
}
.footer{
    height: 100px;
    background-color: #20a0ff;
}
@media screen and (min-width:960px) {
    .header,
    .container,
    .footer{
        width:960px;
    }

    .left,
    .main,
    .right{
        float: left;
        height: 500px;
    }

    .left,
    .right{
        width: 200px;
    }

    .main{
        width: 550px;
        margin:0 5px;
    }
    .container{
        height: 500px;
    }
}
@media screen and (min-width: 600px) and (max-width: 960px){
    .header,
    .container,
    .footer{
        width: 600px;
    }
    .left,
    .main{
        float: left;
        height: 400px;
    }
    .right{
        display: none;
    }
    .left{
        width: 160px;
    }
    .main {
        width:435px;
        margin-left: 5px;
    }
    .container{
        height: 400px;
    }
}
@media screen and (max-width: 600px){
    .header,
    .container,
    .footer{
        width: 400px;
    }
    .left,
    .right{
        width: 400px;
        height: 100px;
    }
    .main{
        width: 400px;
        height: 200px;
        margin-top: 10px;
    }
    .right{
        margin-top: 10px;
    }
    .container{
        height: 420px;
    }
}